1. Technical Field
The present invention relates to a printing control apparatus and a printing control method.
2. Related Art
An ink jet printer is known which performs printing by discharging the ink onto a printing medium, using a printing head including a plurality of nozzle rows in which a plurality of nozzles capable of discharging a same type of ink are arranged in a nozzle row direction. In the ink jet printer, when one nozzle discharges the ink, a spiral air current (eddy air current) is generated in the vicinity of the nozzle according to discharging. Such eddy air current affects the ink discharged from the other nozzles in the vicinity. Specifically, the eddy air current causes an orbital of the ink discharged using the other nozzles in the vicinity to be disturbed, and causes deviation of a landed position of the ink on a printing medium. Such deviation of the landed position is visible as color unevenness in a printing result. The color unevenness generated by a result of the deviation of the landed position of the ink caused by the disturbance of the air current, such as the eddy air current, is referred to as wind ripple.
Moreover, an ink jet recording method is known in which the image data is allocated so that the number of discharging times the recording element rows positioned at a forward side of a travelling direction of recording main scanning becomes smaller than the number of discharging times the recording element rows positioned at a backward side in a plurality of recording element rows discharge the same color ink (refer to JP-A-2008-143092).
The eddy air current described above is suppressed by air current (contrary wind) from a forward side of the movement relatively generated due to a movement of the printing head. Accordingly, when a nozzle of the nozzle row positioned at a forward side of the movement direction among the plurality of nozzle rows discharges the ink, a growth of the eddy air current is suppressed, and thus, the wind ripple as described above is less likely to be generated. Meanwhile, when a nozzle of the nozzle row positioned at a backward side of the movement direction, air current from a forward side of the movement described above in which discharging of the ink using the nozzle row of the forward side becomes a type of wall (air wall) barely reaches, and thus the eddy air current is likely to be grow. That is, the ink discharged by the nozzle row positioned at the backward side of the movement direction, a deviation of the landed position is likely to be generated due to the influence of the eddy air current, as a result, the wind ripple is generated.
With respect to such a problem, as disclosed in JP-A-2008-143092, it is a concern that the growth of the eddy air current at the time of discharging the ink using the nozzle row positioned at the backward side of the movement direction is suppressed, by reducing the number of discharging times of the nozzle row positioned at the forward side of the movement direction. Meanwhile, by using the plurality of nozzle rows called the forward side and the backward side of the nozzle row at a same ratio, image quality is improved (for example, high printing resolution in the nozzle row direction can be realized). Accordingly, reducing the number of discharging times of the nozzle row positioned at the forward side of the movement direction in order to suppress the wind ripple, does not always achieve the best result.